76 GEOLOGY OF OLD HAMPSHIRE COLTNTY, MASS. 



THE KOWE SCHIST = THE LOWEK iSERICITE- OK HYDROMICA-SCHIST. 



For two-thirds of the way across the State, starting from tlie north, 

 the stratum between the albitic mica-schist below and the inteiTupted horn- 

 blende-seqientine band (the Chester amphiboHte) is a thick but extremely 

 monotonous bed; and as for the purpose of working out the architecture 

 of the region every valid distinction needs to be utilized, I have marked 

 this bed separately from the Hoosac scliist as far south across the State as 

 practicable. It is the rock of the first 7,000 feet of the Hoosac Tunnel. 

 In Hampden County, as already indicated, it becomes feldspathic, and can 

 not be easily distinguished from the liand below, as it is followed south 

 from that region. 



FRANKLIN COUNTY. 



The scliist enters Franklin County from the south, across the line 

 between the east portal of the tunnel and the great serpentine deposit at 

 E. King's, nearly a mile east, and, with high dips to the southeast, bends 

 around the south end of the Green Mountain gneiss, and extends, with a 

 width of a mile, northeast into Vermont. 



At the tunnel portal and east to the serpentine it is a very quartzose, 

 pale-green, hydromica-schist, stretched so that it has often a ligniform 

 structure. It contains a few garnets, trapezohedra, and many flattened 

 lenses of quartz, which rarely contain dolomite. 



Followed northeast, where it crosses the Rowe-Moiu-oe road it is very 

 chloritic in its upper portion, and at the base is a dark, rustv mlca-schi.st, 

 resemliling the Conway schist. 



A thin section was cut from the rock 4,000 feet from the east portal of 

 the tunnel ; it is a light-gray, schistose rock of greasy feel, a true sericite- 

 schist, from whose powder the magnet removes mucli magnetite. It shows 

 under the microscope a mosaic of fine quartz grains, dusted with magnetite 

 and wrapped around with muscovite and pale-green chlorite scales. 



HAMPSHIRE COUNTY. 



As the Rowe scliist crosses Middlefield it has the same monotonous 

 character. It is, however, more garnetiferous, and the garnets are very 

 generally chlorite-bordered, and on foliation faces blotches of chlorite 

 appear mixed with the hydrated mica. 



